[3][1] Some of DDoS-Guard's notable clients have included American alt-tech social network Parler, and various groups associated with the Russian state.

[3] In 2021, a researcher observed the DDoS-Guard appeared to have no physical presence in Belize and had likely incorporated there to gain access to IP addresses normally only allocated to local entities.

Of more than 11,000 IP addresses assigned to DDoS-Guard's two subsidiaries, the researcher found two thirds had been provided to the Belizean company by LACNIC, the regional Internet registry responsible for Latin America and the Caribbean.

[5] On 1 June 2021, cyber-intelligence company Group-IB reported that they had found DDoS-Guard's database, containing site IP addresses, names, and payment information along with its full source code, for purchase on a cybercrime black market forum.

[3] Some of DDoS-Guard's other clients have included the Palestinian Islamic militant nationalist movement Hamas,[1] the cyberstalking site Kiwi Farms,[9] and the imageboard 8kun, formerly known as 8chan, which is the online home of the American far-right QAnon conspiracy theory.

[3] DDoS-Guard also provides services to The Daily Stormer,[15] an American neo-Nazi, white supremacist, and Holocaust denial website and message board.

The company said that they stay out of politics and they receive thousands of abuses claiming that their customer violates the law, but "no legal proofs".

[14] DDoS-Guard briefly provided denial-of-service attack protection to online stalking and harassment forum Kiwi Farms after Cloudflare canceled services to the site on 3 September 2022.

[23] In 2017, a U.S. court ordered all internet infrastructure companies to stop doing business with Sci-Hub, the shadow library which shares scholarly papers without regard to copyright.

[25][8] Sci-Hub founder Alexandra Elbakyan says that DDoS-Guard initially contacted her, and that the company volunteered that it works with piracy sites including Rutracker.org.

[25] Elbakyan says she pays DDoS-Guard about US$1,000 per month (one sixth of Sci-Hub's operating budget), all for DDoS protection; an expert found this amount credible.